You're surely familiar with the following guiding principle: "What's not consumed doesn't have to be generated". In the field of pneumatics, roughly 70% of all lifecycle costs are attributed to energy consumption. Leakage alone is the cause for up to 30% of all compressed air consumption, which can quickly add up to energy costs in the tens of thousands of dollars per year for individual companies.
The potential energy savings when taking all scenarios into account is great, potentially cutting as much as 50% of overall energy consumption. First, you should clarify which energy costs result from your compressed air system. Next, you’ll need to implement the following measures for energy efficiency:
This manual provides practical tips and tricks for saving energy in the field of pneumatics. Examples and explanations make implementation easy. Our knowledge, our experience and our products can be found in this manual.
Download: Energy savings manual (PDF)
One of the most important measures for increasing energy efficiency comes after commissioning the system: employees and users should be made aware of the energy-saving functions they are working with. In the end, sustainability is only possible with continuous training of the respective personnel.
Selection, dimensioning, and coordinated interaction amongst the compressors are the beginning and end. This also includes approaches such as central heat recovery and speed control for the compressors.
Suitable compressor sizing with common controller can reduce energy costs by up to 20%. And alone in the compressor station, up to 96% of all generated heat can be recovered.
An unnecessarily high-pressure level within the system should be reduced – under certain circumstances by breaking the system down into several networks. Energy savings amounting to up to 10% can be achieved by reducing system pressure by 1 bar.
Some machines require a continuous minimum pressure as a precautionary measure. If individual applications require higher pressure levels, this can be accomplished in a decentralized manner with the help of pressure boosters.
It’s advisable to use pneumatic fittings with minimal flow resistance within the piping network. The feed lines to the systems and the pneumatic valves or valve manifolds should be adequately large in order to prevent pressure loss.
Good compressed air treatment not only extends the lifetimes of components and systems, it increases productivity and industrial energy efficiency at the same time as well. Diligence in this regard pays off in a lasting manner.
Suitable sizing of compressed air treatment is important, with regard to service unit components as well. For example, every compressed air filter represents a natural resistance, which increases energy consumption.
Use efficient drying technologies with only minimal purge air loss. For example, refrigeration dryers reduce power costs by means of heat exchange between the cold dry air and the warm air that still needs to be dried.
Pressure losses must be avoided. This is achieved by careful selection and dimensioning of the compressed air filters, as well as correct (and controlled) adjustment of the pressure regulators.
Maintenance at regular intervals and correct selection of compressed air treatment can reduce energy consumption by up to 20%. This also includes monitoring of differential pressure at the compressed air filter.
Energy consumption depends decisively on the sizing of the pneumatic actuators: up to 40% of an application’s actual compressed air consumption can be saved by avoiding oversizing.
Measures for energy efficiency begin during the planning stage. It’s best to work with evaluation matrices, cost calculators, and simulation software right from the very start in order to optimize the pneumatic system for the specific application.
Above all, oversized actuators must be avoided. Be sure to lay out the safety factors correctly and keep moving loads small.
Carefully deliberated selection of the actuator type, which is best suited for the application, is also decisive. Single-acting cylinders or a pressure-reduced return stroke can noticeably decrease compressed air consumption. Use pressure regulating plates and pressure regulators.
Be sure to keep pneumatic tubing lengths as short as possible and use well-designed tubing, which reduces flow loss. Above all, we recommend decentralized positioning of the valve manifolds.
Prevent non-productive idling. It should be possible to switch off the entire system, as well as individual segments or components. Be sure to use a safe sequence for shutdown and startup.
Plan for energy monitoring in order to check your compressed air consumption. Fundamentally, all sources of energy should be monitored by means of sensor technology, above all with air flow sensors in the pneumatic system.
Modern vacuum generators for custom handling systems and process engineering require significantly less energy. For example, compact ejectors with energy-saving function are a proven, economical option.
An air-saving circuit should always be used for vacuum applications involving smooth surfaces and non-porous materials. Where vacuum injectors are used, reduce pressure to the respectively optimum level.
The use of blast air for cleaning and cooling can often be significantly improved. Fundamentally, targeted nozzles should be used for blast air and not open sections of pneumatic tubing.
Blast air applications should be operated in a clocked, pulsed, and pressure-reduced manner. A conventional 2/2-way directional control valve is used for clocking. Festo recommends a fast-switching valve for pulsation.
A good maintenance technician is distinguished by low levels of leakage. Examination of the compressed air system at regular intervals and routine checking for pressure drops before the system is started up are equally important.
Don’t forget that leaks which go unnoticed cause unnecessary energy costs 24 hours a day. Leakage rates can be reduced by up to 20% for an average, existing system.
Due to the individual characteristics of pneumatic and electric systems, no generalized statement can be made concerning which technology should be chosen. This decision always involves economic considerations.
An appropriate combination of both technologies is frequently the best solution. This applies above all to control and installation concepts, which are based on decentralized, networked intelligence.